1. Field of the Invention
The present invention relates to a radio communication system utilizing a plurality of mobile terminals having radio communication functions via a mobile phone or other communication network and to a mobile terminal used in such a system, more particularly relates to a radio communication system that centrally manages current positions and situations of a plurality of mobile terminals able to acquire their own locating information at a management apparatus (management center) and a mobile terminal used in such a system, and to a radio communication method.
2. Description of the Related Art
In recent years, it has become common for mobile phones, one type of radio communication terminal, to be equipped with camera modules. Images captured by mobile phones provided with camera modules are transmitted (delivered) to other persons via a wireless communication network.
When using a mobile phone provided with this camera module, the user operates a shutter key to capture an image. On the other hand, there is a demand for enabling objects to be photographed at locations where there is no one present by enabling remote control of the image capturing operation of mobile phones provided with camera modules. To meet this demand, a mobile phone taking a picture in response to an image capturing request sent by radio communication has been proposed (Japanese Unexamined Patent Publication (Kokai) No. 2003-143261).
Since mobile phones and other mobile portable terminals now mount camera modules, it has been proposed to utilize these mobile portable terminals for security systems equipping policemen, guards, or engineers with mobile portable terminals, centrally managing security based on information from the mobile portable terminals via a wireless communication network such as image information and voice information from the carriers at a management apparatus (management center), and issuing instructions and mobilization commands to the carriers of the mobile portable terminals from the management center based on this information.
In the currently proposed systems etc., however, while it is possible to collect information from mobile portable terminals such as image information and voice information from the carriers via a wireless communication network, the management center side cannot obtain the positional information of the carriers of the mobile portable terminals. Accordingly, where for example a carrier of a mobile portable terminal moves etc., it is difficult for the management center side to maintain a determine of his correct position. Also, when a certain carrier requests assistance and the center wishes to request another carrier to go help, the center cannot determine there is any carrier located near the carrier requesting assistance and has trouble transmit accurate information to the carrier who can rush there fastest. Further, the carriers of the mobile portable terminals make rounds of the areas assigned to them in advance, but the management center side has trouble determining the current positions of the carriers of the mobile portable terminals and has trouble centrally managing the entire system.